Game.supply = function(viewWidth) {
	this.type = Math.floor(Math.random() * 2);
	this.isAlive = true;

	this.img = new Image();
	if (this.type == bloodSupply) {
		this.width = 29;
		this.height = 45;
		this.img.src = './images/supply_02.png';
	} else {
		this.width = 30;
		this.height = 45;
		this.img.src = './images/supply_01.png';
	}
	this.x = Math.floor(Math.random() * (viewWidth - this.width));
	this.y = 0 - this.height;
}

Game.supply.prototype.move=function () {
	this.y+=4;
}